Re-Evaluation of EP45 Gravity Modelling with the Assistance of Detailed Aeromagnetic Data

Abstract

Recently acquired detailed aeromagnetic data, over a large portion of EP45, displayed four major anomaly patterns. Sketching the extent of the dolerite and basalt onto the Bouguer Gravity contour map indicates a correlation between the high density dolerite and the gravity highs. The lack of positive gravity anomalies associated with the basalt can be explained by the fact that there is little density contrast between the basalt and the Tindall Limestone (Telford average density Basalt 2.79g/cc, Dolomite/Limestone 2.70g/cc). The Cambrian cover is fairly uniform in thickness and so where there is a thin sequence of basalt, the Tindall Limestone thickens accordingly.

It was suggested that the gravity highs caused by the dolerite may have masked Roper Group sequences in previous gravity modelling